Operation Progression - How does it work?

I am currently power leveling a new character in order to jump into Operations. How does the progression work in SWTOR? I know Eternity Vault seemed to be the first but is it even done anymore? I see the "Black Hole Commendation" things but do you basically use those to get replacement gear and skip the first couple of operations and jump into the new content? Would appreciate anyone who can explain this for me.

You will start with the first flashpoints and will get ther columi and rakata gear. This is already tier 2-3. Also you can run in the dungeon finder both Karaggas Palace and Eternity Vault to get even more gear. Both of them are really fun when you learn them the first time and they provide a really good mixture of tactics and design. Also will there many randoms group who try to form hc runs to both already mentions operations and Explosive Conflict. You will can enter them after you get to columi/rakata in most slots without burden your camerades..